# Session 0034.0 — Transcript

> App: vscode-cowriting-plugin
> Start: 2026-06-12T03-28 (PST)
> End: 2026-06-12T03-39 (PST)
> Type: planning-and-executing
> Posture: autonomous (yolo)
> Status: **FINALIZED**

## Launch prompt

`/goal next` → resolved from memory to: plan-and-execute #38 (undo renders wrong
marks in the F10 review preview, P1).

## Plan

Fix #38 (P1). Root cause (confirmed by reading + E2E repro): attribution attributed
every non-seam change to currentAuthor() (always human), ignoring e.reason — so
undo/redo re-inserting text falsely colored it human. Fix: geometry-only span
reconciliation on undo/redo (no fresh attribution). E2E repro → minimal fix → green.

## Arc (systematic debugging)

- **Phase 1 (root cause):** traced the three data sources feeding the pure
  `renderReview` (baseline diff / F3 author spans / F4 proposals). Read
  `attributionController.onDidChange` + `attributionTracker.applyChange`: every
  non-seam change is attributed to `currentAuthor()` (always human) and `e.reason`
  is ignored. Proposals only shift (not the culprit). Disk-sync guard masks
  undo-to-saved-state → bug is on mid-edit undo.
- **Reproduce:** wrote `test/e2e/suite/undoMarks.test.ts` driving edit→edit→undo
  (mid-edit, buffer stays dirty). Confirmed FAILING: after undo, `spansFor` =
  `[{start:6,end:12,author:"human"}]` over restored "bravo " — false attribution.
- **Fix (Phase 4):** `applyChange` gains `attributeInserted` (default true);
  `onDidChange` sets it false and skips seam matching when
  `e.reason === Undo|Redo`. Restored text stays neutral, not falsely human.
- **Verify:** repro passes; +3 unit tests for the geometric-only path. 197 unit +
  50 E2E green; typecheck clean.
- **Shipped:** PR #39 merged → main; issue #38 closed.
- **Follow-up filed #40** (type/task, P3): restore *exact* prior provenance on
  undo/redo (the fix leaves undone text neutral, not its original author color);
  needs an attribution history stack synced to the editor undo stack.

## Cut state

`main` clean + synced; 0 open PRs. #38 fixed and closed; #40 filed. 197 unit + 50
E2E green. No deploy pipeline (VS Code extension).

## Deferred decisions

1. **Scoped the fix to "neutral on undo," not exact provenance restoration.**
   Alternative: an attribution history stack that restores each char's original
   author on undo/redo. Why deferred: synchronizing such a stack with VS Code's
   undo (which coalesces edits) is fragile, and the neutral fix already removes the
   reported misleading marks. Tracked as #40 (P3) so it isn't lost.

## Next /goal

```
/goal plan-and-execute #33 (intra-emphasis sentinel hardening) via the token-aware HTML-post-process approach recommended in the issue #33 comment, per specs/coauthoring-interactive-review.md §1.7/§9
```

(Backlog: #40 undo provenance (P3); #32 scroll-sync (feature, needs a Solution
Design); #35 repo rename (outward, operator timing).)